Immunomodulatory Effect of Propolis on Foxp3 Gene Expression in Human Peripheral Blood Mononuclear Cells Stimulated in vitro with Pseudomonas Aeruginosa Ag

Immune balance during infection is critical for both supporting the defense of the immune system of the body and preventing an overly aggressive immune response. Foxp3, a transcription factor of regulatory T cells, plays a critical role in balancing the immune system of the body. Propolis has been shown to affect Foxp3 expression. This study aimed to verify the effect of propolis extracts on in vitro Foxp3 gene expression in peripheral blood mononuclear cells (PBMCs) stimulated with Pseudomonas aeruginosa Ag. In this study, a total of 20 apparently healthy volunteers were included, with 10 males and 10 females within the age range of 20-40 years old. Five ml of blood were drawn from each participant to assess Foxp3 gene expression in PBMCs using density gradient lymphoprep and stimulated with P.aeruginosa lipopolysaccharide (LPS) in vitro. The samples were divided into four distinct groups as follows: LPS stimulated PBMCs, ethanol-extracted propolis (EEP) + LPS stimulated PBMCs, and water-extracted propolis (WEP) + LPS stimulated PBMCs and PBMCs as the control group. The Foxp3 gene expression level was estimated in all four groups following a period of 48 h of cultivation by real-time polymerase chain reaction technique using SYBR green dye. Results of the study indicated that propolis had a great effect on the mRNA Foxp3 expression. Both EEP and WEP had immunomodulatory effects through the Foxp3 mRNA expression, both the EEP and WEP could significantly inhibit Foxp3 mRNA gene expression by human PBMCs after stimulation with pseudomonas Ag in vitro. Propolis exhibited an immunoregulatory effect which was the same with ethanol and water extracts on Foxp3 mRNA gene expression.